The purpose of this study is to identify factors that influence the recruitment, retention, and adherence of female injection drug users (IDUs) in HIV/AIDS clinical trials. Despite recent efforts to improve the recruitment of minorities, women, and IDUs, the under-enrollment of these groups into HIV trials persists. We are currently conducting an HIV/AIDS clinical trial that enrolls exclusively female IDUs (280 HIV+ and 320 HIV- women) in inner city Baltimore. Participants have learned about the trial mostly through word-of-mouth from friends and on the street, suggesting that social networks play an important role in the recruitment of this risk group into clinical trials. Although social influence, especially by friends, has been found to affect drug use and other health-related behaviors, little has been done to characterize how social networks may affect recruitment, retention, and adherence in an HIV/AIDS clinical trial. The behavioral model for vulnerable populations may also provide an appropriate theoretical framework for approaching the issue of adherence in clinical trials. This study has three specific aims: (1) to characterize the role of social networks among female IDUs in recruitment, retention, and adherence in an HIV/AIDS clinical trial, (2) to identify factors that women identify as barriers or facilitating factors to recruitment in a trial, and (3) to identify factors associated with poor retention and adherence of women in a trial. To address these aims we will examine the knowledge, attitudes, and practices and characterize social networks of women being screened and followed in our ongoing HIV/AIDS clinical trial. The role of social networks and various factors in predisposing, enabling, and need domains of the behavioral model for vulnerable populations will be examined in relation to recruitment, retention, and adherence. We will also determine the perceived barriers and facilitating factors to participation and retention in a clinical trial. This pilot study should identify factors that are associated with recruitment, retention, and adherence of minority female IDUs in an HIV/AIDS clinical trial and should provide evidence-based rationale for future interventions to facilitate the recruitment, retention, and successful participation of this risk group in HIV research trials.